Pharm Chapter 49: Immunizing Drugs

Immunizing Drugs

-Active immunizing drugs consist of vaccines and toxoids that may be given either orally or intramuscularly and work by stimulating the humoral immune system. -The antibody titer measures how many antibodies to a given antigen are present in the blood and assesses whether enough antibodies are present to protect the body effectively. -If the antibody levels decline over time, another dose of the vaccine is given to restore the antibody titers to a level that can protect the person against the infection—a booster shot. -Toxoids are altered forms of bacterial toxins that stimulate the production of antibodies in the same way as vaccines. -Immunocompromised patients may not benefit from receiving vaccines or toxoids; they may need passive immunizing drugs such as immunoglobulins. -Passive immunizing drugs are the actual antibodies (immunoglobulins) that can kill or inactivate the pathogen. -The successful immunization of 95% or more of a popula- tion confers protection on the entire population. This is called herd immunity. -Antivenins, also known as antisera, are used to prevent or minimize the effects of poisoning by the venoms of crotalids (rattlesnakes, copperheads, cottonmouths, and water moccasins), black widow spiders, and coral snakes. Most healthy adults do not die from the bites of spiders or snakes if they receive prompt and appropriate treatment; however, very young children and elderly adults are particularly susceptible to the effects of the venom of some of these animals. -Most antivenins are obtained from animals (usually horses) that have been injected with the particular venom; however, the newer ones are produced by recombinant technology. The serum contains immunoglobulins that can neutralize the toxic effects of the venom. -Contraindications to the administration of immunizing drugs include allergy to the immunization itself or any of its components, such as eggs or yeast. Patients who should not receive immunizing drugs include those with active infec- tions, febrile illnesses, or history of a previous reaction; use of these drugs in pregnancy is also usually contraindicated. -Undesirable effects of the various immunizing drugs can range from mild and transient to serious and even life threatening; the overwhelming majority of adverse effects are minor. -Serum sickness sometimes occurs after repeated injections of equine (horse)-derived immunizing drugs. -Any serious or unusual reactions to immunizing drugs need to be reported to the Vaccine Adverse Event Reporting System. This national vaccine safety surveillance program is cosponsored by the U.S. Food and Drug Administration and the CDC. -At one time, it was thought that thimerosal (a mercury- containing preservative used in vaccines) may have been a causative link between vaccines and autism, so since 2001, thimerosal has no longer been used in the preparation of vaccines. In 2011, the medical community declared that the original study suggesting a link to autism was fraudulent. It is suggested that the original author falsified the medical histories of the patients in his study. -Some vaccines are not to be given close in time to one other. Review the package insert to obtain the latest information and identify other specific drug interactions that may occur. -The Institute for Safe Medication Practices has reported errors that involve incorrect use of two vaccines that are used to immunize patients against diphtheria, tetanus, and pertussis (whooping cough). Adacel (Tdap) and Daptacel (DTaP) have similar official names but are used in different situations and for different patients. -DTaP contains toxoids of diphtheria and tetanus as well as the acellular pertussis vaccine for pediatric patients 6 weeks to 6 years of age. -Tdap contains tetanus toxoid, reduced diphtheria toxoid, and acelluar pertussis vaccine and is used as a booster vaccine for older children, adolescents, and adults. -Haemophilus influenza type b vaccine is a noninfectious, bacteria-derived vaccine that is given by injection to adults and children considered at high risk for acquiring H. influenzae infections, including septicemia, pneumonia, cellulitis, arthritis, osteomyelitis, pericarditis, sickle cell anemia, an immunodeficiency syndrome, and Hodgkin's disease. -In 2014, a new vaccine called Trumenba was approved. It is the only vaccine that prevents invasive disease caused by Neisseria meningitidis serogroup B in individuals 10 through 25 years of age.

Anatomy, Physiology, and Pathophysiology Overview

-A foreign substance in the body is termed an antigen; the body creates a substance called an antibody specifically to bind to it. When the body first comes into contact with antigens from an invading organism, specific information is imprinted into a cellular "memory bank" of the immune system. The body can then effectively fight any future invasion by that same organism by mounting an immune response. -B lymphocytes (B cells), when stimulated by the binding of an antigen molecule, begin to differentiate into memory cells and plasma cells. Memory cells remember what that particular antigen looks like in case the body is exposed to the same antigen again in the future. Plasma cells manufacture antibodies, immunoglobulin molecules that have antigen-specific amino acid sequences, and will mass-produce clones of the antibodies upon reexposure to a particular antigen. -The two types of immunity are: (1) active and (2) passive immunity. Different types of drugs are used to induce each, and these drugs are indicated for different populations, as follows: • Active immunization involves administration of a toxoid or a vaccine that exposes the body to a relatively harmless form of the antigen (foreign invader) to imprint cellular memory and stimulate the body's defenses to fight any subsequent exposure. It provides long-lasting or permanent immunity. The recipient must have an active, functioning immune system to benefit. • Passive immunization involves the administration of immunoglobulins, antitoxins, or antivenins. Serum or concentrated immunoglobulins are obtained from humans or animals and, after screening and testing, are injected into the patient, directly giving the individual the ability to fight off an invading microorganism or inactivate a toxin. Passive immunization provides temporary protection and does not stimulate an antibody response in the host. It is used in patients who are immunocompromised or who have been exposed to, or anticipate exposure to, an organism or toxin. -Active and passive immunization can both be an artificial or natural process. -In artificial active immunization, the body is clinically exposed to a relatively harmless form of an antigen that does not cause an actual infection. Information about the antigen is then imprinted into the memory of the immune system and the body's defenses are stimulated to resist any subsequent exposure (by producing antibodies). -In contrast, natural active immunization occurs when a person acquires immunity by surviving the disease itself and producing antibodies to the disease-causing organism. -Artificial passive immunization involves the administration of immunoglobulins, antitoxins, or antivenins. Serum or concentrated immunoglobulins are obtained from humans or animals and, after screening and testing, are injected into the patient, directly giving the individual the ability to ght off an invading microorganism or inactivate a toxin. Passive immunization provides temporary protection and does not stimulate an antibody response in the host. It is used in patients who are immunocompromised or who have been exposed to, or anticipate exposure to, an organism or toxin.

Passive Immunization

-In artificially acquired passive immunization, the host's immune system is bypassed, and the person is inoculated with serum containing immunoglobulins obtained from other humans or animals. This confers temporary immunity against a particular antigen following exposure. -Important examples include immunization with tetanus immunoglobulin, hepatitis immunoglobulin, rabies immunoglobulin, and snakebite antivenin. -Passive immunization occurs naturally between a mother and the fetus or the nursing infant when the mother passes maternal antibodies directly, either through the placenta to the fetus or through breast milk to the nursing infant. This is called naturally acquired passive immunity. -Passive immunizing drugs are also used in people who already have the given disease, especially those with diseases that are rapidly harmful or fatal, such as rabies, tetanus, and hepatitis. Because these diseases can progress rapidly, the body does not have time to mount an adequate immune defense against them before death occurs. -The passive immunizing drugs are divided into three groups: (1) antitoxins, (2) immunoglobulins, and (3) snake and spider antivenins. -Antitoxin is a purified antiserum usually obtained from horses inoculated with the toxin. -An immunoglobulin is a concentrated preparation containing predominantly immunoglobulin G and is harvested from a large pool of blood donors. • An antivenin, often referred to as antivenom, is an antiserum-containing antibodies against a venom, poison secreted by an animal such as a reptile, insect, or arthropod (e.g., spider).

Active Immunization

-Substances of biologic origin are used to prevent, treat, or cure infectious diseases (e.g., vaccines, toxoids, and immunoglobulins). These drugs are often simply referred to as biologics. Biologics also refers to drugs of bioterrorism (e.g., anthrax spores, smallpox virus), depending on the context. Toxoids and vaccines are known as immunizing biologics, and they target a particular infectious microorganism. -Toxoids are substances that contain antigens, most often in the form of bacterial (usually gram-positive bacterial) exotoxins, detoxified or weakened (attenuated) with chemicals or heat, which renders them nontoxic and unable to revert back to a toxic form. -Toxoids remain highly antigenic and can stimulate an artificial active immune response (production of antitoxin antibodies) when injected into a host patient. -Current versions of toxoids are effective against diseases such as diphtheria and tetanus caused by toxin-producing bacteria. -Vaccines are suspensions of live, attenuated (weakened), or killed (inactivated) microorganisms that can stimulate production of antibodies against the particular organism. Today there are more than 20 infectious diseases for which vaccines are available. New vaccines appear periodically but not with the rapidity of other types of drugs, because of the complexities of developing a safe and effective vaccine. -Current goals include finding vaccines against human immunodeficiency virus infection/acquired immunodeciency syndrome and malaria. The ultimate goal is to develop an effective vaccine against all infectious diseases.

The anthrax vaccine is recommended for which groups of people? (Select all that apply.) A. Military personnel B. Veterinarians C. Workers who process imported animal hair D. Emergency department health care providers

A. Military personnel B. Veterinarians C. Workers who process imported animal hair People at risk for exposure to the anthrax bacterium include military personnel, veterinarians, and workers who process imported animal hair.

Which statement MOST accurately describes the pharmacodynamics of vaccines? A. Vaccines work by stimulating the humoral immune system. B. Vaccines provide IgG antibodies to protect against infection. C. Vaccines prevent the formation of antibodies against a specific antigen. D. Vaccines work by suppressing the amino acid immunoglobulin sequence.

A. Vaccines work by stimulating the humoral immune system. Vaccines work by stimulating the humoral immune system, which synthesizes immunoglobulins. They also stimulate the formation of antibodies against their specific antigen, providing active immunity.

What teaching would the nurse provide to a client receiving tetanus toxoid? A. "You will have lifetime immunity from this injection." B. "Soreness at the injection site is a common reaction." C. "This medication must be repeated weekly for 4 weeks." D. "Increase fluid and fiber in your diet to prevent constipation."

B. "Soreness at the injection site is a common reaction." Soreness at the injection site is a common adverse effect of tetanus toxoid.

The current immunization for tetanus and diphtheria toxoids and pertussis, Tdap, is administered to people in which age range? A. Younger than 6 years of age B. 11 years of age and older C. Any age range D. In the first 2 years of life

B. 11 years of age and older Currently, DTaP is the preferred preparation for primary and booster immunization against these diseases in children from 6 weeks to 6 years of age unless use of the pertussis component is contraindicated. Tdap is the recommended vaccine for adolescents and adults, those over the age of 11 years.

What is the priority nursing assessment to monitor when administering vaccinations? A. Myalgias B. Anaphylaxis C. Symptoms of infection D. Pain at the injection site

B. Anaphylaxis Anaphylaxis is a potential life-threatening adverse reaction to vaccines. Pain and myalgias can occur but are not life threatening.

An allergy to which substance is a contraindication to the administration of an immunizing drug? A. Soy B. Egg C. Corn D. Wheat

B. Egg Contraindications to the administration of immunizing drugs include allergy to the immunization itself or allergy to any of its components, such as eggs or yeast.

Which vaccination is marketed and recommended in the prevention of a virus that is known to cause cervical cancer? A. Herpes zoster vaccine (Zostavax) B. Papillomavirus vaccine (Gardasil) C. Pneumococcal vaccine (Prevnar 13) D. Hepatitis B virus vaccine (Recombivax HB)

B. Papillomavirus vaccine (Gardasil) Human papillomavirus virus (HPV) is a common cause of genital warts and cervical cancer. The HPV vaccine (Gardasil, Cervarix) is the first and only vaccine known to prevent cancer.

Which vaccination was developed to prevent bacterial meningitis caused by Haemophilus influenzae? A. Prevnar B. Gardasil C. Hepatitis B vaccine D. Hib conjugate vaccine

D. Hib conjugate vaccine H. influenzae type b (Hib) (HibTITER, ActHIB, Liquid PedvaxHIB) vaccine is a noninfectious, bacteria-derived vaccine. Before this vaccine was developed, infections caused by Hib were the leading cause of bacterial meningitis in children 3 months to 5 years of age.

Administration of which substance provides passive immunity? A. Vaccines B. Toxoids C. Antitoxins D. Immunoglobulins

D. Immunoglobulins Vaccines, antitoxins, and toxoids provide active immunity by stimulating the humoral immune system. Immunoglobulins provide passive immunity by giving the patient substances to fight specific antigens.